Scissors-tool pivot



July 7, 1925. 1,545,211

C.R.STORZ scISsons TooL P1voT Filed July 21. 1922.

Patented July 7, 1925.

; UNITED STATE CHARLES R. STORZ 0F NEW YORK, N. Y. v

, SCISSORS-TOOL PIVOT.

Appucationmei July 21.

new and useful Improvements in Scissors- I' Tool Pivots; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming partfofV this specification.

This invention relates to a` pivot for use with such tools as have two cooperating arms and also relates to the tools themselves, particularly to scissors ofthe usual types.

In practically all scissors thepivot is a screw which has a threaded engagement with one of the blades and has at its free end a cylindrical journal surrnounted by a head kerfed in the usual manner for the reception of ascrew driver. Pivots of this nature are adjusted bytightening thescrew until the proper friction between the blades is secured and then the threaded portion in the screw is locked against rotation vwith the blade by deforming the screw by punching, or by welding, or in some other' manner.' The scissors then have a pivot permanently secured to one of the blades and have thev other blade pivotally mounted on the 'headed end of the screw so that the head of the screw and the blade mounted thereon turn with respect to each other as the scissors are operated and unless the threaded portion ofV the pivot is secured to the other blade in some manner the pivot soon loosens. On the other hand if the pivot is permanently se'- cured to the under blade the scissors soon become loose due to the `wear of the parts and frequently it is quite impossible to tighten them.

It is the object of the present invention to eliminate these disadvantages of scissors pivots and vto provide a pivot which will have no tendency to unloosen and one in which the head of the adjusting screw will be immovable with respect to the proximate blade during the cutting operation. This adjusting screw has a threaded engagement with the pivot journal while the lower blade turns freely with respect to the upper blade, the adjusting screw, and the pivot journal;

the latter three parts moving as a unit in' the normal cutting operation.

In the drawings,-'

1922. serial No. 576,621'.

Figure 1 is a bottom plan view of a pairv of scissors embodying the present invention,

the head of theh adjusting screw being considered'as being on'the topface of the scissors.

i Fig. 2 is a transverse cross section through the pivot.

Fig. 3 is atop plan view ofthe pivot member or bushing. l Fig. lis an elevation thereof.

The scissors illustrated in the drawings are ofthe detachable blade type which 'type scissors is rapidly displacing the older type of scissors in which the arms and cutter blades are integral. The detachable blades form no part of 4the presentinvention, how-A PATENT OFFICE.`

ever, except in combination and the pivot is equallyuseful onv scissors of the older type an'd'other 'tools' employing a pair of pivoted members or arms. l

The cutter blade carrying larms 10 and 11 hereafterwcalled the upper and the lower arm forv convenience ofy description, each carry a thin steel detachable cutting blade 12 adapted to' be secured to the arms 10` and l11 -by fastenings 14 of the cling blade type so that a dull blade maybe removed with little yor no difficulty and may be replaced by ra sharp one inthe same man-` ner as a safety razor blade is removed. The

arms 10fand 11 each carry ahandle 15 of the usual configuration so that when closed the scissors closely resembles the older type.

The pivot of the present invention is materially different, however from the or-v dinary pivot and consists of vtwo cooperating members, one an ordinary headed screw 16 which fits within the internally threaded axial opening 17 through the bushing 18, the head of the screw being of such size as to overlie the upper face of the arm.y 10. If desired the screw head 16 may be countersunk in the armV 10 in accordance with quite usual practice but the form illustrated is deemed preferable.

yThe bushing 18 is generally cylindrical but has two plane side faces 20 extending slightly more than half way down the bushing leaving a true cylindrical portion 21 which forms a pivot journal, this journal portion merging into the circular head 22 adaptedl to fit into the countersunk portion4 28 in the lower arm 11. It is obvious thatv the head 22 need notv be circular and also need not be received within a countersunk portion but inay overlie the arin 11 in the Y saine ni'aniierasxthe lhead of the screw 16 iii the preferred form overlies the arno I 10,' the purpose of the heads being to hold ther-twof-l arnis assembled in pivotal relation-.1

The bushing 18 is slotted as at 25 for a portionfof its length in` order to ni'orelse'scurely hold the adjusting screw 1G in desired position. The portionspir-either side:v

of the slot or slit 25 inay be resilient to einbrace the screw or'ifdesired the non-circular orifice' v27 infthe'farin l() inay; be'v 'slightly' saperi-idl as shown in Fig; 2.'1 i The hold-"27 lis preferablythe 'exact vshape of` the crosssecv'tion of the bushing through the two plane' 'inthe process of inanufac'ture although ob- Vviouslyjthev upper bladeI l2 niight have 'a pi'vot hole which" would"correspond 'to-the hole 27', and theV shoulder hwould-thenbe placed just beneath'the plane of 'the' cooperating Vfaces ci the two cutter blades.

To assemble the device the bushing. 18 inserted iii vthe two-idiani'eter' bore ofthe lower arn'illll and the bushingis thenpushed into ther nonlci'rcular hole27 until lnearly the correct aniount'iof'friction-is secured.'

The screwl 16 is now inserted vintlie AcentralV 'threaded opening of the bushing andjis tightened until'theexact 'amount of friction has been obtained and the scissorsare thenWV ready for use; Since the bushing! 1S 'is locked to turn with the arm 10 and since the' adjusting screwy16 valsoturns with this bladeit is obvio-u'sfthatfthere is no tendency of--any'kind for the screw to unloosen and thatqthe bush-ingfisfreely rotatable within 45 the lower arm l1.

It frequently happens with the older types of scissors where the screw pivot is not de- 'orn'i-ed that vthe#scissors will work nicely until they are oiled, but oiling will causer the pivot` toloose'n; In-"thepresent" construction'tliis disadvantage ldoes Vvnot y:obtain siiicefthere isi no relative lnfi'oveiiient between the 'screw' and the bushiiigfor the arno 10.*

It' should' 'also' be obvious-'that an eXtrein-e nicety of adjust'inent ispossiblefasthethreadsk on" the lscrew 4and'lbushing nia-y be very lshallowf As the *bearings-wear 'the adjustment may .be maintainedby a 'very slightturningJ of the 'screw with a"screwfdr`iver*frornitinie 60" to tinie. I Y

What I'clai-in" is:

said arin's' having a Ycircular fopening therein and .the other Aa none'circul'arl *tapered* open 65 ing,'1an internally'threaded bushing having a 4circular portion fitting the 'circular openl ingjinv one ainfiandL havinganon-circular portion fitting said non-circular tapered4 opening, theopposite'sides'of said non-'cirl' 70 cular portion of' "the bushingbeing flaftand' extending. substantially parallel 'toeach otheil' the non-circularL portio'iro'l' the bush# inglbetweeii'said 'fiat faces 'being slottedv and Paw* semi-circular:with the'arcs 'formed `by' its 5" senililciroularl surfaces struck 'onU -they sani-eVV radiusas the circular' portion of theb'ushing,'Vv and a headed screw securedin "said bushing; 

